摘要
Abstract
Objective To explore the application effect of low dosage and low concentration of contrast agent combined with different weights of ASIR-V in portal vein spectroscopy CT examination.Methods We collected 84 patients who underwent portal vein CT enhancement examination at the First Affiliated Hospital of Bengbu Medical University from November 2023 to April 2024 and then randomly divided into A and B group,with 42 cases in each.In group A,the patients underwent energy spectrum CT combined with 60%adaptive statistical iterative reconstruction-V(ASIR-V)scanning.The iodine contrast concentration used was 320 mgI/mL,and the contrast agent dosage was calculated as 1.2 mL/kg.Additionally,single energy images ranging from 40 to 80 keV were extracted from the original data at 10 keV intervals.The portal vein images of 20 subgroups were reconstructed using ASIR-V with increments of 20%(ranging from 20%-80%).Group B underwent a CT scan with conventional CT combined with a 0%ASIR-V preposition,iodine contrast concentration of 350 mgI/mL,and a contrast agent dosage calculated at 1.5 mL/kg.Images with 120 kV were automatically output with a 0%ASIR-V preposition.The CT values,noise(SD),signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR)of the largest portal vein main layer,as well as the liver parenchyma and erector spinal muscle of the same layer,were measured and calculated in both groups.Subsequently,the imaging diagnostic physician conducted a subjective assessment of the image quality.Objective image quality indicators and the amount of contrast agent were analyzed using independent sample t-test and Kruskal-Wallis H test,while subjective image indicators were assessed using the Kappa consistency test.Results The increase in post-ASIR-V weight resulted in a significant decrease in image noise(P<0.001)and an increase in both SNR and CNR.In group A,the background SD of 60keV,with 60%ASIR-V preposition and 60%ASIR-V postposition,was 26.06±3.95 HU,significantly higher than that of the control group(18.80±2.39 HU)(P<0.001).Additionally,SNR and CNR were significantly higher than those in group B(P<0.001).The iodine intake and the effective radiation dose in group A were significantly lower than those in group B(P<0.001).Although the subjective score of group B was slightly higher than that of group A,the difference was not found to be statistically significant.Conclusion The quality of portal vein images obtained through energy spectrum CT using low-dose and low-concentration contrast agents,combined with anterior and posterior ASIR-V,is comparable to those obtained through conventional CT enhancement.This approach has the potential to significantly reduce radiation dose and iodine intake,making it suitable for clinical application.关键词
能谱CT/门静脉/ASIR-V权重水平/辐射剂量/对比剂Key words
energy spectrum CT/portal vein/ASIR-V weight level/radiation dose/contrast agent
